


Mistake

by CHESSERE



Category: Ensemble Stars! (Video Game)
Genre: Aged-Up Character(s), Alternate Universe - Canon Divergence, Alternate Universe - Magic, Alternate Universe - Succubi & Incubi, I Don't Even Know, Is this allowed, M/M
Language: English
Status: Completed
Published: 2019-07-27
Updated: 2019-07-27
Packaged: 2020-07-23 05:08:29
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,782
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20002810
Author URL: https://archiveofourown.org/users/CHESSERE/pseuds/CHESSERE
Summary: Tsumugi summons an Incubus by mistake and that incubus doesn't want to leave him alone.





	Mistake

**Author's Note:**

> Prompt: Scholar/alchemist Tsumugi x succubus/incubus rei. Basically, just antics where Tsumugi accidentally summons rei and then can’t get rid of him (and then falls in love with him in the process)

"Eeh!?!?" The glasses man yells after a figure with dark, flowing hair and horns shows up in the middle of the magic circle.

Looking at his surprised face, he didn't think this spell would work, did he? Well too late, Rei's here. And he's more than glad to have someone to play with after such a long time.

"My, my, what a bad kid, summoning an incubus like me."

Rei lets out a chuckle as he walks toward the younger man and put his hand on his cheek, speaking with his face too close to the other for his own good. Tsumugi could even see his bare fangs.

"Wait, an i-incubus!?" The younger man exclaimed in panic before he pushes Rei and opens his book to check on something.

"..."

"I, I used the wrong spell!"

Wrong spell? What did he mean by the wrong spell? Learning how that kid summoned him by mistake angers Rei. He's not some kind of a low-level monster that anyone could just summon by mistake.

"Well...sorry, but is there a way for me to unsummon you? I'm going to get in trouble for sure..." He asked politely as if it would help with anything. Rei just smirks at him.

"There's n-o-n-e. You summoned me, so take responsibility, young man~" Rei said as he stretches his wings out and flies around a heartbroken man who's shaking in nervousness.

The truth is, there is a way, but why would Rei tell him? Messing with Tsumugi sounds a lot more fun than just wandering around aimlessly for sure.

"No way..." Tsumugi mumbles as Rei laughs next to him.

...

"What's thaT" Natsume asks Tsumugi who was shocked by seeing a succubus that he accidentally summoned several days ago next to him.

"Aah! I said please don't follow me to school!" He pushes Rei away.

How boring, Tsumugi doesn't look like he's interested in him at all and that drives him mad. He _is_ a succubus and he can't even charm a nerdy boy who in all seriousness, would _never_ get laid if he continues to be like _this_

"Oh, Is this your friend, Tsumugi-kun? My apologies, I should introduce myself, shouldn't I?" He chuckles as he retracted his wings and land his feet on the ground elegantly.

"My name is Rei Sakuma, as you can see, I am an incubus"

"An incubuS. So you're like thiS, huh, TsumugI" Natsume just give him a blank stare like his opinion of the man went from low to lowest, and that's pretty amusing if Rei has to say.

"No! It's not what you think, Natsume-kun!" Tsumugi fidgets around with nervousness.

"Well, how is it theN?"

"It was an accident! I used the wrong summoning circle and, uh, the next thing I knew was I summoned him." Tsumugi fidgets around. Pretty cute if you'd ask Rei. This was the first time he was ever summoned by a man this young so it was a refreshing situation at least.

"So you're saying that you, of all things, summoned an incubus by accidenT?" Natsume speaks before he sighs, probably thinking that his older classmate is an idiot.

The bell rang, telling the student in the campus that the next period is starting. Tsumugi jumps a little then run to his class before he becomes late.

Natsume is skipping this period anyway so he's not following the older man. A little yellow bird flew down next to him then turns into a human a few seconds later.

"Master! Sora is back--...?" The small boy silently looks at Rei in confusion.

"Why don't he just unsummon yoU, doesn't he realize there's a spell for iT?" Natsume asked. But instead of answering, Rei just makes a little 'shh' sound and flash out a mischievous smile before he flies away with his pairs of black wings.

"Oh, so Tsumugi was really an idioT" the red-haired boy shakes his head then turns to his familiar.

"Let's go have something to eat Sora, I'll deal with him next timE" he smiles as the small boy jumps around in excitement.

...

A pure white dove stands in front of Rei looking at him with curiosity before it flies around then turns into a human who looks like he was the same age as Rei.

"Amazing! I've never seen an incubus before! I'm sure Kanata-kun would be surprised too to see a real-life incubus here!" The person said

What could Rei say, the person in front of him is quite obnoxious, to be honest. He's just casually looking at him while going 'Amazing!' until he's satisfied.

Well, not that he minds, his summoner always tries to ignore him all the time so it's pretty nice to have someone appreciate his beauty like this.

"Hm?" Rei makes a little sound as the other person drags him by his arm to somewhere.

A lake behind the campus? Why would he want Rei here? But before he could ask any questions, he saw a big shadow lurking underwater.

"A fish?"

"Ah! Just wait a little!" The long-haired boy told him, and the next thing he sees is a figure emerges from the pond.

"Wataru? What are you doing 'here'? Do you want to 'puka puka' with me?" That figure turns out to be another boy who's soaking wet in the pond for some reason, and the reason is probably that he's a fish.

"Oh, not right now, maybe later. But look, Kanata-kun! It's an incubus!"

So the fish boy's name is Kanata, Rei thinks he seems like a nice person, not as loud as the dove.

"Yes, I am indeed a real incubus right here~" Rei stretches his wings and shows them to the boy with blue hair while chuckling with his deep voice

"Now, it's rude to not introduce yourself, right? My name is Sakuma Rei."

"My apologies! I got too excited and forgot about that. I am your very own Hibiki Wataru, a familiar of the student council president, Eichi Tenshouin!" Wataru's self-introduction is long and loud, the polar opposite of the other boy's.

"I'm 'Kanata Shinkai'~ as you can 'probably' see, I'm a fish that's been 'protecting' this lake for a long time~ Would you like to 'puka' with me?" Kanata slowly introduces himself too.

"Oh, I'll pass, you see, I'm not very good with water" Rei smiles as Kanata makes a slightly disappointed face.

"Ah, it seems like Eichi has been calling for me. I shall take my leave then! See you later, Kanata, Rei!" After he bids farewell, Wataru turns into a dove again then fly back to the campus.

"Well then, I'm going back to Tsumugi-kun too, nice to meet you Kanata" Rei smiles lightly as he also flies away from the lake

"Nice to meet you, Rei~" Kanata disappeared into the water after he finished his sentence.

...

"Where have you been!?" Tsumugi is huffing as Rei lands down in front of him.

"I was at the lake behind this campus with Wataru-kun and Kanata-kun. What do you want?" Rei asks while playing with his silky black hair.

"Wait, are you possibly, worried about me?" He squints his red eyes looking at the glasses boy.

"Well, I mean, I'm worried that you might cause some problem...being a demon after all" He looks away

"That's mean. I'm not a kid anymore, you know," Rei laughs

"Or are you worried that I'd go seduce someone else other than you? My, my what, a cute kid~"

"I don't think a 20 years old could be called a kid anymore though..." He scoffs, but Rei just laughs at him.

"Oh dear, you're certainly a kid for me for sure."

Almost everyone who has ever summoned Rei was at least almost a hundred years old and somewhat beyond human for sure, since he's not easy to summon. How this nerd who's just a magic student, let alone _human_ accidentally summoned him here still pisses Rei off greatly.

"W-We should go home..." Tsumugi pushes his glasses and turns around

"As you said~" Rei lifts himself up from the ground and flies next to him

...

Rei doesn't feel good.

It's been several months since he's here and he's getting more and more tired lately. So this is how it feels without anyone to satisfy his nature, huh.

"Um...Are you okay?" Tsumugi crouch down to Rei who's lying inside Tsumugi's house library, in the middle of the same magic circle which was used to summon him

"Huh...oh it's nothing, I'm just tired, that's all." Rei voice is slow and dull, unlike his usual speaking voice which always hides a slight playful undertone.

"..."

"It's an incubus thing, isn't it?" Tsumugi asked

Using his small amount of energy he has left, Rei lets out a chuckle and answers.

"Well, you probably already know it already."

"..."

"T-This is the most I could offer" Tsumugi stutters before leaning down and press his lips on Rei's nervously. Which surprised him to some extent.

How bold, maybe Rei could change his mind about Tsumugi never getting laid but that's not important right now. Tsumugi pulls away as Rei sits up.

"Kuku, you've left me starving, kid" Rei pauses the kiss to speak, before slightly biting down on Tsumugi's lower lip, savoring every moment of it. Rei _is_ an incubus after all, of course, it's what he normally does but it seems like this is quite new for the person on the other side.

Rei breaks the kiss and then laugh dryly since the energy he got was still not enough for him to return back to his normal self.

"Look, this is why I call you a kid." Rei is still laughing at Tsumugi who was blushing profusely while trying covering his face with his hands.

He fell into the demon's trap, of course, Rei would want more, it's like a contract that after avoiding it for so long, Tsumugi finally forges it without realizing.

Maybe this is not too bad, except for the starving part, this nerdy boy is quite entertaining for Rei.

...

"Tsumugi-kun" Rei speaks up, hearing that, Tsumugi turns his head to look at the floating demon beside him.

"What?"

"There's actually a way to unsummon me." He just casually says it and fly upward. Earning a surprised yelling from Tsumugi

"H-Huh!?"

"Well, even if you decided to unsummon me now, I'm not going anywhere. You're stuck with me, kid~" Rei speaks before flying away somewhere in a carefree manner.

"Well then, what shall I do today~" Rei is thinking about probably going to hang out with Wataru and Kanata at the lake like the usual again and maybe tell him about what happened since he disappeared for so long.

**Author's Note:**

> Alternative description: Rei makes fun of Tsumugi for being a nerd and a virgin.
> 
> This was not what I'm good at yet this fic contains one of the best lines I've ever written up until this point and I don't know how to feel about it fjdklsha;
> 
> Please enjoy once again!


End file.
